The Galapagos Plume Geodynamics, a Geochemical Approach

加拉帕戈斯羽流地球动力学，一种地球化学方法

• 批准号: 0403107
• 负责人: Alberto Saal
• 金额: $ 12.53万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0403107&HistoricalAwards=false
• 关键词: Galapagos; Plume; Geodynamics; Geochemical; Approach

SaalEAR-0207136 The goals of this study are to provide additional constraints to improve our knowledge of the Galapagos plume and its interaction with the Galapagos Spreading Center. Two scientific issues pertaining to the geological evolution of the Galapagos will be addressed as part of this study. Firstly, in order to understand which processes are responsible for the geochemical variations of the Galapagos lavas and which current model is most suited to explain them, we propose a study that combines oxygen and radiogenic isotope analyses with major and trace elements compositions on the same sample set. Secondly, we propose to develop a geodynamic picture of the upwelling velocities and melting of the mantle beneath the Galapagos archipelago. Traditionally, geodynamic pictures of mantle upwelling and melting have been obtained through detailed geophysical studies. In the last 15 to 20 years, the study of U-series (238U-230Th, 230Th-226Ra, 235U-231Pa) has allowed scientists to image the mantle upwelling and melting using a geochemical tool. In contrast to other radiogenic isotope systems, the short half lives of the U-series will allow us to get a first look at the present-day mantle composition, the extent of melting represented by a suit of lavas and estimate the mantle upwelling at different points in the archipelago. The combination of U-series, oxygen and other radiogenic isotopes with major and trace elements contents measured in the same samples combined with ongoing geophysical studies, will provide our best opportunity to obtain a reliable geodynamic image of the Galapagos plume and the surrounding asthenosphere.

SAALEAR-0207136这项研究的目标是提供其他限制，以提高我们对Galapagos羽流的了解及其与Galapagos扩展中心的相互作用。本研究的一部分将解决与加拉帕戈斯地质演变有关的两个科学问题。 首先，为了了解哪些过程负责加拉帕戈斯熔岩的地球化学变化，以及哪些当前模型最适合解释它们，我们提出了一项研究，将氧和放射原同位素分析与主要样品集合的主要和痕量元件组合结合在一起。 其次，我们建议开发一幅关于加拉帕戈斯群岛下落速度上升速度和地幔融化的地球动力学图片。传统上，通过详细的地球物理研究获得了地幔上升和熔化的地球动力图片。在过去的15到20年中，对U系列（238U-230，230th-226ra，235U-231PA）的研究允许科学家使用地球化学工具对地幔上升和融化进行成像。与其他放射性同位素系统相反，U系列的短寿命将使我们能够首先查看当今的地幔组成，这是由熔岩服代表的熔化程度，并估算了群岛不同点上的地幔上的地幔。 U系列，氧和其他放射原同位素与在相同样品中测量的主要和微量元素含量以及正在进行的地球物理研究结合的结合，将为我们提供最佳机会，以获得Galapagos羽流的可靠地球动力学形象以及周围的心磷酸群。